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Topic: 18th century English bottle (Read 1614 times)

Just thought I would share some pics of an interesting bottle purchased on eBay out of the UK. It was listed as a piece of studio glass but was actually a very early bottle. It stands about 4.5 inches tall, is of lead glass and was patterned in a 20 diamond mold. What makes it so unusual is the applied cobalt decorations and applied cobalt blue lip. This bottle is similar to the small English 18th century diamond patterned cosmetic jars but is larger in size than those and with a narrower neck. Here are links to pictures:

I watched it as well. It's gorgeous, but I don't really 'do' that intense blue so I left it. Sorry I can't help on info as I know nothing about bottles, but it's a lovely piece. Your photos show it well, the glass really looks as though it carries it's history with it - it makes me feel as though if you held it you would be in touch with people from the past m

Hi, You, might find that a test for the glass's density is more accurate in determining lead content in an object that has had coloured glass applied ,which can affect the results achieved by the use of a black light ,It is also very a handy test used to help in the dating of early lead vessels ,less lead tending to suggest an earlier date of production.

The density of soda/non lead glass is 2.4 g/cm3 or below, while typical lead crystal has a density of around 3.1 g/cm3 and high-lead glass can be over 4.0 g/cm3 or even up to 5.9 g/cm3"

1. find a container big enough to hold the item so that it can be submerged. Place that container inside another container so that when water runs out of one container it is collected in the one below.2. Fill the first container so that it just starts to pour over the edge (you need to break the meniscus). Then make sure you have no water in the bottom container. Next lower the glass to be measured slowly into the water making sure you don't trap any air bubbles inside the vessel (I would tie a bit of string round it and lower it in that way)When the displaced water has run over the edge into the bottom container measure its volume in ml's and use this (along with the weight of the item) to calculate the density of the glass as follows...

weight of item in grams overvolume of displaced water =density in g/cm3

example,

the item displaced (conveniently) 100ml and it weighed 323grams. Therefore its density was 3.23g/cm3,= lead

I am sure its not a 100% foolproof method considering the many different compositions of glass but its pretty accurate for most things A fun test for all to try . but don't drop anything trying it !!!!!!

That is a very good method Peter! We use that here to determine the density of certain paperweights. There are two glass factories over here that made very similar weights and some of the workers who made them worked at both factories at one time or another, however each factory had a different recipe for their crystal which in turn makes it possible to distinguish which factory made the weight due to the density differences of their recipes. If I ever test this bottle I will post the results.

Attached is a picture of an English 20 diamond salt cellar with a blue rim. I have also seen small 20 diamond cream jugs in clear glass with the blue rim. Also attached is a picture of a 20 diamond blue cream jug of the type I am referring to. I think there is a very good chance my 20 diamond bottle is related to these pieces.

When using the "displaced water" method for calculating density, it might be useful to repeat the process several times under the same conditions and then use the average of all results.

As Peter said, the method is not 100% foolproof, but averaging several measures should give a result that takes some account of hard to control procedures - particularly those needed to ensure the lower container has no water prior to the lowering of the object, and then making sure that the sides of the initial container do not retain some of the displaced water, which could be a problem when using such as a standard, flared plastic bucket with not very smooth sides and various mould ridges!

Another problem to be careful about is that of wave formation at the edge of the initial container. After breaking the meniscus at the edge, any swing of the object during lowering could easily tip excess water over the lip. Swing of the object can be a problem if its form is such that it has to be lowered at an "unbalanced angle" or even moved under water in order to ensure that no air is trapped in any parts. Imagine trying to exclude air from a piece that has a conical foot, a bowl and an everted rim!